Triangular numbers whose sum of squared digits is also triangular.

Terms

a(0) =0a(1) =1a(2) =6a(3) =10a(4) =36a(5) =630a(6) =741a(7) =1081a(8) =2211a(9) =7140a(10) =10011a(11) =10153a(12) =13366a(13) =15576a(14) =17766a(15) =23220a(16) =24531a(17) =25651a(18) =28920a(19) =33411a(20) =42486a(21) =47586a(22) =52326a(23) =59685a(24) =61776a(25) =69006a(26) =112575a(27) =113050a(28) =121771a(29) =125751